Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/724419
28 In Site September 2016 Water. desalination + reuse Suez is developing a model to better understand photovoltaics 1 Suez is involved in two projects with Masdar. The first is piloting a conventional RO system, using dissolved air flotation (DAF) and membrane pre-treatment adapted for conditions in the Gulf, and a double pass RO system. "This is demonstrating that seawater RO is affordable, reliable, and able to reach the target. We have achieved 97 per cent availability of the plant," says Miguel Angel Sanz, director of strategic development, treatment infrastructure, Suez. As the pilot moves into the optimisation phase, the goals are "to optimise every treatment, to minimise energy and chemical consumption, to demonstrate that the new technology is able to reduce operational costs, and ultimately to reduce the water cost", says Sanz. Suez is testing membranes that are already on the market, as well as next generation membranes. The second pilot is a new technology that is being tested in an industrial plant for the first time. It's a system using liquid-to-liquid ion exchange resin technology to increase the volume of water produced without raising seawater intake. It has been developed as part of a partnership between Suez, its shareholder the French energy utility Engie, and Nasdar Institute of Science and Technology, to develop a computer application that can extrapolate pilot data better, to understand how to combine desalination with renewable energy sources. "We are already experts at taking pilot data and extrapolating it for other environments. Through this new partnership we want to create a model that can be used either on the grid or off the grid, powered by a photovoltaic system. We are looking at, 'What is the best way to couple desalination technology and renewables?'," says Sanz. "It's a very good approach because we are doing it in a real partnership with a potential customer, Masdar Clean Energy. It's a unique experience in the world." We are looking at, 'What is the best way to couple desalination tech- nology and renewables?' Miguel Angel Sanz, director of strategic development, treatment infrastructure, Suez Forward thinking • Suez is running two pilots • The first, a double pass RO system, has achieved 97 per cent availability • The second is testing liquid-liquid ion exchange resin technology at a live industrial plant for the first time • Suez and its shareholder, French energy utility Engie, are developing a computer application with Masdar Institute of Science and Technology Masdar aims to support Gulf's move to membranes Masdar Clean Energy set a target for its pilot projects of one cubic metre of water for every 3.6 kilowatt hours of energy used. This is a particularly challenging target in the Persian Gulf, where salinity is very high, the water temperature is high, it's very shallow, and there's high organic matter. The partner firms, Abengoa, Suez, Trevi Systems, Veolia/ Sidem, and Mascara have each signed a separate joint venture partnership with Masdar Clean Energy to pilot their technologies. Each of the initial four projects have met or exceeded the energy efficiency target, three operated very smoothly, and two achieved full availability throughout the nine months. The pilots are hooked up to the conventional electricity grid, the idea being to demonstrate the energy efficiency of the systems, and later to combine them with renewable energy sources. "When membranes were first developed, they were used in countries with relatively good quality seawater. Membranes are dramatically lower in energy consumption compared to thermal distillation, but it's difficult to run these membrane plants in the Gulf, and it's only now that a transition is beginning," says Dr Alex Ritschel, head of technology, Masdar Clean Energy. "Some utilities are very skeptical that reverse osmosis [RO] is the right choice for the Gulf, particularly because systems have been installed and they experienced issues. So to have these pilots up and running, and to show that they work, it's a good message. Many companies and designers are not really aware how difficult the seawater is here. You need really to know how to deal with it, to have the right pre- treatment systems in place, and to understand how to operate the plant in terms of chemical dosing, backwashing, and membrane cleaning. We know now what system configuration will work. AŸer one year of operation we really know. If a plant operates 365 days without any problem then it's pretty good. We have shown it can be done," Ritschel says. The energy efficiency results for each project depend on variables including water temperature, the viscosity of the water, and "many, many other things", says Ritschel. "If you just throw out a number it has no meaning, because you need to know all the boundary conditions under which the value was achieved." An additional fiŸh pilot, a joint venture with French company Mascara, was installed in September 2016, this time testing an RO system that's directly powered by photovoltaics on the roof of the unit. This small scale solution is designed to provide water in remote places with no access to the grid, and is not a utility-scale technology. The next phase of the main four pilots is an optimisation period that runs from September 2016 to spring 2017, during which time the pilot partners will work to squeeze out any further efficiencies in chemical and energy consumption from their designs. Masdar Clean Energy, with its joint venture partners, then expects to begin tendering for projects based on